The Battle of Antietam ended as a strategic Union victory, although tactically it was more of a draw. Union General George B. McClellan successfully turned back Confederate General Robert E. Lee's invasion of Maryland, forcing Lee to retreat back to Virginia. Despite heavier Union casualties and McClellan's failure to decisively defeat Lee's army or vigorously pursue the retreating Confederates, the battle halted Lee's campaign in the North
. This Union "victory" was significant politically because it gave President Abraham Lincoln the opportunity to issue the preliminary Emancipation Proclamation, which shifted the war aims toward ending slavery and discouraged European powers like Britain and France from recognizing the Confederacy
. In summary, while the battle was tactically inconclusive with heavy losses on both sides, it was a strategic Union victory that marked a turning point in the Civil War
